Oil Recommendation for 74 MG

[Wampahoofus]

Greetings BITOGers! Long time lurker, first time poster.

I'm looking for a good oil for my 74 MG Midget with the A Series engine. Factory recommends 20W50, but oil pressure reads high with that. At full temp idle, it never drops below 40 psi, minimum spec is 20 psi so I'm thinking a 15W40 would be a good fit.

From my research so far, Delo 400LE looks great with it's old school high zinc/phosphorus/calcium content. It also seems to be on the thick side of oils in it's class, so the chance of going too thin is slightly reduced.

Any thoughts on other HDEOs like Delvac/Tection/GTX Diesel/Rotella T? With the low SAPS requirement a lot of the good old additives seem to be going away in them. Worried mostly about the flat tappets.

If there are any British BITOGers reading, anybody have experience with the Castrol Classic XL 20W50? I'd like to get my hands on some sometime.

 

[79sunrunner]

WELCOME!!!!! I never worried about zinc in my car do to the low impact levels of smaller engines. Rotella T would be an excellent choice, but for the sake of safety, a Cassie oil like castrol 20/50 XL would be a great choice. And you get an awesome can! You can also get classic oil from Carlube, Morris Lubes, and a few others. Good luck!
Are you a member of any British car forums like MG Experience?

 

[HardbodyLoyalist]

My wife had a '68 MGB. It did well on just about any 15W-40 HDEO, although this was ~10 years ago, when everything was loaded with ZDDP. I'd recommend finding the highest ZDDP HDEO you can easily obtain and giving it a try.

Run a UOA after 4000 miles or so if you're in doubt about its ability to protect.

 

[Bud]

I have owned many MG's over the last 50 years. I have always used 20w50 with never a problem. Used Castrol GTX for many of them but have been using Valvoline VR1 for the last several years on my 71B.

 

[expat]

15w-40 has worked very well in my Triumph Spitfire 1500, I see no reason why it should not work out in your 'A' series.

That OP does seem a little high, what is you Idle speed?
What is the reading at 2,000 rpm Hot?


Oh....

 

[JR]

I ran vr1 for years. ran in ope's and a few older cars and such.

ken

 

[Wampahoofus]

Originally Posted By: 79sunrunner
WELCOME!!!!! I never worried about zinc in my car do to the low impact levels of smaller engines. Rotella T would be an excellent choice, but for the sake of safety, a Cassie oil like castrol 20/50 XL would be a great choice. And you get an awesome can! You can also get classic oil from Carlube, Morris Lubes, and a few others. Good luck!
Are you a member of any British car forums like MG Experience?


I'm not on any British car forums yet, but I'll poke around a bit and check a few out.

Originally Posted By: expat

15w-40 has worked very well in my Triumph Spitfire 1500, I see no reason why it should not work out in your 'A' series.

That OP does seem a little high, what is you Idle speed?
What is the reading at 2,000 rpm Hot?


Oh....

The OP I quoted was at 1,500 RPM hot. I believe that's with a 190F thermostat, but I'm not totally sure.

Lots of love for VR1 20W50 here; I've heard good things about it. I may switch to that if 15W40 ends up being a bit too thin. Also considering Castrol 4T 20W50 bike oil as it's inexpensive and SG rated.

 

[toneydoc]

Valvoline 20w50 motorcycle oil is a great oil and have used it in HD applications many times.

 

[Dave Sherman]

Welcome! I ran Valvoline VR-1 20W-50 in my '77 Midget for a long time. Recently started using Rotella T6 5W-40, which it seems to be happier with in the cold.

Check out britishcarforum.com, good LBC (Little British Car) site as well.

 

[Wampahoofus]

Ah, I was wondering about T6. I very nearly reached for it on the shelf but decided against it at the last minute. If it's treating your seals well, I may try it next time.

 

[expat]

"
The OP I quoted was at 1,500 RPM hot. I believe that's with a 190F thermostat, but I'm not totally sure."

That is a very high idle speed (about twice what it should be) and would certainly account for the high OP reading.

Will it idle slower?
I'm thinking you might have worn throttle shafts on the SU's

 

[Doug Hillary]

Hi,
Wampahoofus - Great little cars. One of my first Engineering tasks was refining the first export version of the Midget in New Zealand - in 1961!

We used Castrolite 20W-20 or XL 20W-30 in the A series engines (Austin-Morris-MG etc)and 10W-30 was a great fit too. Of course the Mini application is what Duckhams originally developed 20W-50 for in 1959!

A good dual rated 15W-40 HDEO would be a good choice. If the engine has been overhauled in recent times Mobil 1 5W-50 would be a good choice

Has it got an oil cooler??? Some Midgets exported had one as part of a "Tropical" kit

 

[expat]

Originally Posted By: Doug Hillary
Hi,


We used Castrolite 20W-20 or XL 20W-30 in the A series engines (Austin-Morris-MG etc)and 10W-30 was a great fit too. Of course the Mini application is what Duckhams originally developed 20W-50 for in 1959!

l" kit


Remember the Mini used the engine oil in it's transmission also.
They were mot separate systems.

 

[Doug Hillary]

Hi expat,

Originally Posted By: expat


Remember the Mini used the engine oil in it's transmission also.
They were mot separate systems.


Oh I remember the Austin 850/Morris Mini very well indeed - refining the first CKD pack/rebuilt export Mini was my first Engineering project - in December 1959. We had no 20W-50 so we used Castrol's XXL 30-40 lubricant IIRC. Typically it sheared, caused oil pump/drive issues and leaked at every possible point on the engine. Castrol produced it's 20W-50 later and was available in NZ during late 1960 or so

Most annoying of all were ignition issues in the wet - rubber gloves helped a little there.......There were many many issues, believe me!

The A & B Series and even the C Series engines were great - the B in particular!!

 

[expat]

[/quote]

Most annoying of all were ignition issues in the wet - rubber gloves helped a little there.......There were many many issues, believe me!

The A & B Series and even the C Series engines were great - the B in particular!! [/quote]

A rubber glove with the tips of the fingers cut off over the Distributor, and a Prophylactic over the coil.
I remember the later BMC 1100/1300's being even worse in that respect.

Getting back to Oil, I seem to remember 20w-50 being used in just about everything British during the 60's and 70's.
I didn't really see 10w-30 until I came to North America.

 

[Doug Hillary]

Hi,
expat - Yes, the "new" 20W-50 became a "fixit" for British cars even when it wasn't needed - it's still used today by many car owners for the same purpose!!

The A engines with an oil cooler lived well on 20W-20 or 20W-30/10W-30 without

 

[Wampahoofus]

Originally Posted By: expat
"
That is a very high idle speed (about twice what it should be) and would certainly account for the high OP reading.

Will it idle slower?
I'm thinking you might have worn throttle shafts on the SU's


I had the idle set too high when I checked...hadn't yet cleaned out the old SUs. It idles just fine at the spec 1000 now and still pulls about 35 psi.

Originally Posted By: Doug Hillary
Hi,
Wampahoofus - Great little cars. One of my first Engineering tasks was refining the first export version of the Midget in New Zealand - in 1961!

We used Castrolite 20W-20 or XL 20W-30 in the A series engines (Austin-Morris-MG etc)and 10W-30 was a great fit too. Of course the Mini application is what Duckhams originally developed 20W-50 for in 1959!

A good dual rated 15W-40 HDEO would be a good choice. If the engine has been overhauled in recent times Mobil 1 5W-50 would be a good choice

Has it got an oil cooler??? Some Midgets exported had one as part of a "Tropical" kit


Well, sir, my hat is off to you. Whether or not it seemed like it at the time, you were really part of something special there. My car does indeed have an oil cooler. I'm not sure if it was originally sold in the southern part of the US but I can't imagine it was standard equipment for a car here in WI. It hasn't been overhauled, 51,000 mi and still going.

Sounds like pretty much any HDEO will be great. I'm going to change it with the Delo this weekend...will report back.

 

[Doug Hillary]

Hi,
Wampahoofus - It may be wise to keep an eye on the oil temperature as IIRC the oil cooler is not regulated. We used to cover them in NZ in the winter

An IR temperature reader is good for such things - I use a Raytek MiniTemp, a great little device

 

[expat]

In the UK the 1275cc 'A' Series was used in the base model Morris (Austin) Marina. When I started work in the early 70's we had one in the company Pool Car.
Everybody hated it, as the 'other' cars, 2 Liter Ford Cortinas, were far more powerful.
The word was, to Kill it, to be rid of it.
In the lower gears it was revved until the Valves bounced (or perhaps the points?) several times I had taken the car to the North of England Literally with the 'Pedal to the metal' for hours at at time.

Darn thing would not die!

It is one tough engine, and because of that it's an engine with Heaps of potential for tuning.
The word used to be: start with a Long center branch (LCB) exhaust manifold. Or get David Visard's book.
http://www.youtube.com/watch?v=ow5cGV7bXCw

 

[Wampahoofus]

I changed the oil over the weekend with 15W40 Delo 400LE and a Puro Classic (L10028 if I remember right). Pressure actually went up - 45 psi at hot 1000 RPM idle, almost immediately hits the 65 psi relief. The old stuff smelled so badly of gas it probably thinned to a 30 weight >.< I also leaned out the idle jets by about 10-15 flats too. Oy...I want to change it again to make sure all that gas is out.

Expat, I will definitely look into Visard's book. I saw a Youtube clip for it and it sounds like there's some good info in there.